When monogenēs is used to refer to Christ, many English translations use begotten to translate that word, especially when used as an adjective to son (huios). John 3:16 would be the most famous example with the translation, “only begotten son.” We must understand, however, that monogenēs is a compound word, derived from monos—one or only–and genēs–a kind of something (we derive the term genus and its basic meaning from genēs). Hence, quite literally, monogenēs means one-of-a-kind and thus is used to depict something unique or singular. In biblical usage, monogenēs appears four times in the Septuagint (LXX), each time translating the Hebrew term yahid, which means “only,” “sole,” or “lonely.” Specifically, Judges 11:34 uses the term for Jephthah’s daughter as an only child. Two more occurrences in the Psalms use yahid to depict one’s unique self (22:10; 35:17). Finally, in Psalm 25:16, yahid is used to depict being lonely. In no case does the LXX use of monogenēs show any hint of addressing the individual’s essential nature or manner of origin. Rather, the term is always used in contexts of singularity or loneliness.
The New Testament uses monogenēs nine times. It occures three times in Luke’s Gospel, always in reference to only children (7:12; 8:42; 9:38). The Book of Hebrews makes a more distinctive use of the term, calling Isaac the monogenēs of Abraham (Heb. 11:17). It is interesting that Isaac is labeled solely with the term monogenēs. (The word for “son” is not used in the Greek text.) It seems self-evident that in this case, monogenēs cannot be intended to mean an only child, for Isaac had several half-siblings. Rather, the term is used to designate Isaac as unique and singular from anyone else, even his half-siblings. Isaac was the only son of Abraham born through miraculous means and through whom the covenant promise and Abraham’s name was to pass. No other son of Abraham could claim such an origin, blessing, and mission. So the author of Hebrews, because he is using the term to emphasize Isaac’s unique singularity, is clearly not using the term to refer to issues of origins and essential nature. All the biblical data surveyed thus far favors one major focus of monogenēs, namely uniqueness and singularity.
By contrast, there is a Greek word for begetting, gennaō. When used with a female subject, it means to bear an offspring (in humans or other animals) or to give birth. For the male subject, it means to sire an offspring, often translated in old English as “beget.” In the passive voice—which is the most dominant use in the New Testament—gennaō means to be born. Thus, this word has to do with procreation and birthing but, as in English, the biblical writers sometimes use the word metaphorically of things other than procreation (1 Cor. 4:15; 2 Tim. 2:23; Philemon 1:10). (John makes regular use of gennaō for spiritual birth—being born again, born of God.) If we exclude the uses of gennaō in reference to the birth of Christ to Mary in Bethlehem, the New Testament includes only the verses in which gennaō is used in reference to Christ. All three occurrences quote Psalm 2:7.
In the first text, Acts 13 contains a Sabbath sermon by Paul to the synagogue in Antioch in Pisidia. In verses 32 and 33, Paul declares, “‘We declare to you glad tidings—that promise which was made to the fathers. God has fulfilled this for us their children, in that He has raised up Jesus. As it is also written in the second Psalm: “You are My Son, Today I have begotten You.”’”[*]
Paul explicitly ties the decree of Psalm 2:7 to the resurrected Jesus and places the begetting mentioned in the text not back in eternity, but after the resurrection and ascension. Paul is using the text exactly the same way as the Hebrew text does, namely as a metaphor for installation into an office or function and is arguing that after the resurrection of Jesus, there was an installation ceremony to His kingship as prophesied in Psalm 2, and which fulfilled the ancient promise of the permanent messianic Davidic king. Both the installation context, with its metaphorical use of the birthing language, and the chronological timing of the pronouncement to the ascended Christ exclude this text as a basis for concluding that there was some kind of pre-creation begetting of Christ by the Father. Psalm 2:7 says nothing about a begetting back in eternity.
Hence, Hebrews matches Paul’s other writing and the psalmist in using birthing language metaphorically. Furthermore, the author of Hebrews clearly puts the inauguration of Christ’s priestly ministry in heaven after the cross. Hence, Hebrews 5 also applies Psalm 2:7 to the post-ascension Jesus, not to some kind of begetting back in eternity. It seems highly probable that this post-ascension installation into the high priest’s office is the referent for Hebrews 1:5 as well, especially if we believe that the inspired author is using Psalm 2 consistently in both places.
It seems safe to conclude that these texts offer no support for the view advocating a begetting of Christ by the Father back in eternity. Rather, they use Psalm 2:7 in its design parameters, found especially in Psalm 2:6, namely to depict the concept of installing into an office.
In the New Testament, neither monogenēs nor the uses of gennaō in the three quotes of Psalm 2:7 provide any platform for building a theology claiming that Jesus was begotten, sometime back in eternity, by the Father. By contrast, Christ is ascribed with the full attributes of deity, including self-existence (John 1:2, 4; 5:26), creation (Col. 1:16, 17; Heb. 1:2), and sustaining the world (Col. 1:19; Heb. 1:3). The great glory of the gospel is that God chose to inhabit human flesh, assume a human nature, to be our saving substitute from the penalty and power of sin.
* Unless otherwise noted, all Scripture texts are quoted from the New King James Version.